Fig. 1: Chiral Raman response of 1T-TaS2 and its temperature dependence.
From: Spectroscopic visualization and phase manipulation of chiral charge density waves in 1T-TaS2
a Optical picture of mechanically exfoliated 1T-TaS2 flake. b AFM image and the thickness of the 1T-TaS2 sample. c Chiral Raman spectra of 1T-TaS2 excited by left-handed (σ+) and right-handed (σ−) circularly polarized light at room temperature. d Raman intensity difference (Iσ+–Iσ−) extracted from c after removing the background. e Helicity-resolved Raman spectra of 1T-TaS2 at room temperature. f, g Raman intensity mapping of Eg5 mode of the 1T-TaS2 flake under the f σ+ and g σ− laser excitation. h, i False-color Raman spectra showing the variation of Raman intensity as a function of temperature under the h σ+ and i σ− excitation, which shows the chiral Raman response for different CDW phases. The white dotted lines approximately illustrate the temperature ranges for the commensurate (C), nearly commensurate (NC), and incommensurate (IC) CDW phases according to the variation of chiral Raman intensities. The red, yellow, and blue arrows indicate the Eg5, A1g2, and A1g3 Raman modes, respectively. The two white arrows in i represent Eg6 and Eg7 modes, which can only be detected for σ− excitation. The wavelength of the excitation laser is 532 nm.
